1. Field of the Invention
The present invention relates to a cleaning sheet suitable for use in maintaining a recording apparatus in which sheets of recording medium composed of coated paper are used to conduct recording, a cleaning method of a recording apparatus with such a cleaning sheet, and a stack of recording medium containing such a cleaning sheet.
2. Related Background Art
In a recording apparatus equipped with a paper feeding means for feeding one recording paper sheet from stacked plural sheets of recording paper (a pile of recording medium) toward a recording section of the recording apparatus in contact with a recording surface of the recording paper sheet, there has heretofore been widely used a paper feeding system provided with a separating means for separating a recording medium from stacked sheets of the recording medium for preventing a multi-sheet feed that plural sheets of recording medium are fed in piles, which occurs in the course of the feeding. FIG. 1 illustrates an exemplary recording apparatus equipped with such a separating means for a recording medium. The recording apparatus illustrated in FIG. 1 will hereinafter be described.
In FIG. 1, reference numeral 1 designates a paper feed tray. Sheets of recording medium 2 stacked thereon are successively fed onto a platen 9 in the following manner. Namely, when paper feed rollers 3 (feeding means) in the form of a semicylinder, which are provided over the recording medium 2, are rotated counterclockwise on their axis, the feed rollers 3 come into contact with a recording surface of the recording medium 2, so that the recording medium 2 is fed toward the platen 9 with the rotation of the feed roller 3.
A separating means in the recording apparatus illustrated in FIG. 1 is a separation pad 4 provided before the platen 9. The separation pad 4 is in contact with a back surface of the recording medium 2 upon the feeding of the recording medium 2. If two or more sheets of the recording medium 2 are fed in piles, the recording medium 2 in piles are separated from each other by utilizing frictional force between the pad 4 and the back surface of the recording medium 2. As a result, only one recording medium 2 among the stack is conveyed onto the platen 9 by a conveyor roller 5. An image is recorded by a recording head 6 on the recording medium 2 conveyed through the conveyor roller 5 to a recording section of the recording apparatus. Thereafter, the recording medium 2 on which the image has been recorded is discharged through a paper discharge roller 7 and stacked on a paper discharge tray 8.
FIG. 2 is a schematic view of a recording apparatus viewed from the above for the purpose of illustrating a flow of a recording medium in the recording apparatus. In an example illustrated in FIG. 2, a separation claw 10 is provided as a separating means. In FIG. 2, reference numeral 1 designates a paper feed tray. Similarly, as described in FIG. 1, sheets of recording medium 2 stacked on the paper feed tray are fed by rotating a paper feed rollers 3 (feeding means) in the form of a semicylinder and contacting the rollers 3 with a recording surface of the recording medium 2. The recording medium 2 thus fed is conveyed onto a platen 9 by a conveyor roller 5. Upon the paper feeding, only one sheet is separated by the separation claw 10 provided at a corner of the paper feed tray as illustrated in FIG. 2 and fed. The system making use of this separation claw is well known. As illustrated in FIG. 2, the separation claw 10 is so constructed that it is engaged with a corner of a stack of recording medium so as to separate only one sheet upon making good use of the stiffness of the paper. Reference numerals 5, 6, 7 and 8 have each the same meaning as those mentioned in FIG. 1.
On the other hand, in recording using inks of many different colors, in particular, in a full-color ink-jet recording system, coated paper composed of a base material and a coating layer containing a pigment provided thereon is widely used as a recording medium because it is excellent in coloring ability with inks and ink absorbency and can provide a clear image. However, when a recording medium having, in particular, the above-described coating layer is continuously used in quantity in the above-described recording apparatus which has a separating means for recording paper sheets stacked and can conduct continuous recording, a failure of paper passage often occurs due to the influence of paper dust (pigment and the like) fallen off from the coating layer, which poses a problem.
In order to solve such a problem, Japanese Patent Application Laid-Open No. 5-69654 has proposed a cleaning sheet in which a layer having a specific adhesive property is provided on its surface. More specifically, when the sheet is fed into the course of conveyance in a recording apparatus, the paper dust fallen off from the coating layer is stuck to the layer having the specific adhesive property and removed from the course of conveyance, thereby cleaning the recording apparatus. Since this sheet is provided with the adhesive layer on its whole surface, however, the cleaning sheet itself may jam in the recording apparatus in some cases according to use conditions though its cleaning effect can be fully achieved. In addition, in the above-described cleaning sheet, the adhesive layer is provided only on the front surface thereof, so that its cleaning effect on portions of the conveying means, with which the back surface of the sheet comes into contact, is insufficient though its cleaning effect can be sufficiently exhibited on portions of the paper feeding means and the conveying means, with which the front surface comes into contact.
Japanese Patent Application Laid-Open No. 8-175041 describes a cleaning method of an image forming apparatus in which a heating member is brought into contact with a heat-sensitive recording medium to form an image, and the use of a cleaning sheet provided with an adhesive on a part or the whole of the front surface thereof.
As an example of such a cleaning sheet, a sheet obtained by coating a part of one surface of a base material with an adhesive and roughening another part of the surface is described. With respect to this cleaning sheet, it is described to clean a thermal head by rubbing the thermal head with the roughened region of the cleaning sheet and to clean a hot stamp for image erasing by pressing the adhesive region of the cleaning sheet against the hot stamp.
As another example of the cleaning sheet, a sheet obtained by coating a part or the whole of one surface of a base material with an adhesive and roughening a part or the whole of the other surface is also suggested.
However, the function of the roughened region of the surface opposite to the adhesive surface is not described at all. In addition, the degree of roughening is also not described.